Engine



Dec. 31, 1940.

w. c. CONOVER 2,227,247

ENGINE Filed Dec. 4, 1939 5 Sheets-Sheet 1 Z Z INVENTOR WEE/BEN C. C ONOVEE MAM/44,4

ATTORNEY? Dec. 31, 1940.-

w. c. CONOVER 2,227,247

ENGINE Filed Dec. 4, 1 939 5 Sheets-Sheet 2 INVENTOR WaezE/v CT Carve nee,

7 ATTORNEYS Dec. 31, 1940. w. c. CONOVER ENGINE Filed Dec. 4, 1959 5 Sheets-Sheet 3 INVENTOR WHERE/v C. C QNoA ER ATTORNEY .1

Dec. 31, 1940. w. c. CONOVER ENGINE 5 Sheets-Sheet 4 Filed Dec. 4, 1939 Willlllllllillll 1 III-m 21M, M MA ATTORNEYS Dec. 31, 1940.

w. c. CONOVER 2,227,247

ENGINE Filed Dec. 4, 1939 5 Sheets-Sheet 5 INVENTOR J XQQEE/v C CO/ Qz/EE ATTORNEY5 Patented Dec. 3 1, 1940 UNITED STATES PATENT OFFICE- ENGINE Warren 0. Conover, Waukegan, Ill., assignmto Outboard, Marine a Manufacturing Company, Waukegan, 111-, a co poration of Delaware Application December 4, 1939, Serial No. 307,443

2% Claims. (01. 123-173) i This invention relates to improvements in en- Fig. 4 is an end elevation of the engine as it gines. appears with the cylinder head removed.

Generically, it is the primary object of the Fig. 5 is a view of the inlet and exhaust castpresent invention to provide novel and improved ing showing the inner face applicable to the facengine constructions with particular reference ing illustrated in Fig. 3. to the location and formation of cores, passages Fig. 6 is a side elevation of the plate which and Jackets to facilitate the die casting of the intervenes between the casting as shown in Fig. 3 engine cylinder and crank case structure. In and Fig. 5. this connection, it is a major purpose to provide Fig. 7 is a view in elevation of the interior face for the die casting of most of the cylinder blocks of the cylinder head as it appears when removed 10 and crank cases in single operations, whereby in from the cylinder block shown in Fig. 4. each engine so cast the cylinder block and half Fig. 8 is a view in elevation of the gasket which or more than half of the crank case are prefintervenes between the die casting as shown in erably made in one piece, not only to reduce Figsniand '7. l5 assembly costs but to assure perfect alignment. Fig. 9 is a view in vertical axial section through More specifically, the present invention ina single cylinder engine embodying the invencludes among its various objects the provision of tion. means whereby a core for the transfer passage Fig. 10 is a view of the same engine as it apmay be withdrawn through clearance provided pears in a section taken horizontally in the plane in the crank case; to provide novel and improved of the cylinder axis. 2o arrangement and disposition of drilled holes con- Fig. 11 is a view taken in section in the plane s'tituting transfer and fuel admission ports; to indicated at H|l in Fig. 9.

provide novel and improved arrangements of wa- Fig. 12 is a view taken in section in the plane ter jackets to facilitate coring in the construcindicated by the line l2--l2 in Fig. 9.

tion of a die cast engine; to provide a die cast Fig. 13 is a bottom plan view of the engine 25 engine wherein the die cast material is comshown in Fig. 9 as it appears when removed from pacted under pressure upon a cylinder sleeve its support on the shaft housing. incorporated as being inserted in .the die cast; Fig. 14 is a view of the cylinder block casting to provide novel and improved arrangements for of the same engine in side elevation with one of carburetion including an integral unitary organiits side cover plates removed to expose the jacket. 30 zation of fuel tank, crank case, and engine .cyl- Fig. 15 is a view in side elevation of the oppoin'der block in which the principal portions of site side of the cylinder block casting of the same these various devices are die cast in a single engine with its side cover plate removed to expiece; the provision of a novel organization of pose the jacket.

mixture, inlet and exhaust passages whereby such Fig. 16 is a plan view showing a fragment of 35 passages are formed partially in a cylinder block an engine structure slightly modified from the casting and partially in a separate casting and disclosure of Fig. 10. partially by an intervening plate partition; the Fig. 17 is aviewinvertical axial section through provision of novel water passage openings to is.- a further modified single cylinder engine emcilitate die cast construction and circulation bodying the invention. 40 throughout the surfaces to be cooled; together Fig. 18 is a view in horizontal section in the with numerous other objects which will be applane of the cylinder axis of the engine shown parent to those skilled in the art upon study of in Fig. 17. the following disclosure of the invention. Like parts are identified by the same reference In the drawings: characters throughout the several views. 45

Fig. 1 is a vertical axial section through a two The engine shown in Figs. 1 to 8, inclusive, cylinder engine organized for alternate firing on the first two sheets of drawings will first be and embodying the present invention. described. A sleeve 20 of iron or other suitable Fig. 2 is a view in horizontal section through material is cast as an insert into a single die the engine on the center line 22 of Fig. 1 of the casting unitarily providing the dual cylinder block 50 upper cylinder. II and that half portion 22 of the crank case Fig. 3 is a side elevation of the engine as it which is contiguous to the cylinders. The other appears with .the inlet and exhaust ports exposed half 23 of the crank case is removably bolted by the removal of a die casting providing inlet to crank case portion 22 to mom access to the and exhaust passages. crank shaft 24 and connecting rods 25. 55

The cylinder head 26 comprises a separate die casting unitarlly closing the ends of both of the cylinders to receive the compression of the pistons 21 reciprocable therein. As clearly shown in Figs. 1, 2 and 4, the single die casting which provides the cylinders is made to provide also a jacket wall 28 within which there is a jacket space or water passage 29 which, as indicated in Fig. 1 and Fig. 4, is relatively deep along the top and bottom surfaces of the cylinders and, as shown in Figs. 2 and 4, is relatively shallow, as measured from the cylinder head, at the opposite sides of the cylinder-s where the various ports are provided as hereinafter to be described.

The die casting 26 which provides the cylinder head is likewise formed with a jacket to provide a jacket space or water passage 31! as indicated in Figs. 1, 2 and 7. In order that the cylinder head may reach a higher temperature than the cylinders, communication between the water passages 29 of casting 2| and the water passages 30 of casting 26 is preferably materially restricted by the intervening gasket 32 which, as shown in Fig. 8, has relatively small openings 33 which may conveniently be arranged in pairs at spaced intervals to permit water to flow from the cylinder jacket space to the jacket space of the head.

Assuming that the engine is used on an outboard motor and is mounted on the shaft housing 34 of such a motor, the water supply may he led upwardly through the shaft housing and delivered to the channel 35 which surrounds the lower crank shaft bearing, being formed partly in the crank case casting 23 and partly in the casting portion 22 of the cylinder block. As explained in companion application No. 212,078, the admission of cooling water about this hearing serves to protect the bearing from the direct heat of the exhaust which is led below the water line through passage 36 formed in the upper end of the shaft housing in a manner hereinafter to be explained. From channel 35, the cooling water passes through a cooling passage in :a cover casting which provides an expansion chamber and intake manifold as hereinafter described. From this passage, the water returns to the lower part of the jacket space 29 in a manner which will also be described hereinafter. There may, however, be some small amount of flow through a, very restricted opening 31 (Fig. 1) which affords direct communication between channel 35 I and jacket 29 primarily for the purpose of drainage.

The water admitted to the jacket must completely fill the jacket space 29 about both cylinders and the jacket space 36 about the heads of the cylinders before it can escape. The only outlet for the cooling water is through-the vertical duct 38 cast into the cylinder head casting 26 and opening from the jacket space 30 at 39 (Fig. 1) downwardly across the ends of the cylinder heads. This duct opens outwardly at 48 and the water may either be discharged at that point or led by a suitable pipe to any desired place of discharge. In actual practice, there is a pipe (not shown) which returns the water to the exhaust passage tc cool the exhaust gases.

The spark plugs 4| are offset laterally from the duct 38 as shown in Fig. 2. They are prefvided unitarily with arms 43 projecting downwardly and connected by a transverse handle 44 to facilitate the manipulation not only of the engine, but of the outboard motor structure as a whole.

The die cast block in which the engine cylinders are formed is provided with a hollow downward extension at 45 opening at 48 in the direction of the crank shaft 24 to afford communication with the exhaust passage 36 of the shaft housing 34 of the outboard motor. The interior of the hollow extension 45 communicates with a manifold passage 46 which takes the'form of a cavity exposed at the side of die casting 2| and formed by the laterally projecting walls 41 and 48. The wall 48 is a partition between the manifold cavity 45 and the separate cavities 49 and 50 through which the combustible mixture is supplied to the engine. Obviously, the cavities 46, 49 and 58 can conveniently be provided for by a laterally retractible core means.

The laterally upstanding walls about the cavities 46, 49 and 50 are finished to a. common plane to receive a partition plate 55 (Figs. 2 and 6) and a die casting 56 which unitarily provides an expansion chamber 51, a jacket space 58 and a pair of passages 59 and 68 through which the carburetor 6| supplies combustible mixture to the cavities 49 and 58 of the die casting 2|. Die casting 56 is best illustrated in Figs. 2 and 5. The plate 55 has an opening 62 registering with passage 59 and cavity 58 and a. similar opening 63 registering with passage 68 and cavity 49 to afford communication for the flow of combustible mixture to the admission ports 64 of the upper cylinder and the admission ports 65 of the lower cylinder, respectively.

A large opening 66 in the plate 55 affords virtually unrestricted communication between the exhaust passage cavity 46 of the cylinder die casting 2| and the expansion chamber cavity 51 of the separate die casting 56. However, because the partition 68 between the expansion chamber 51 and the jacket space 58 in the auxiliary die casting 56 is offset fromthe partition 48 between the exhaust cavity 46 and the inlet space 58 of cylinder casting 2|, that portion of plate 55 which extends between partitions 48 and 68, as shown in Fig. 2, is imperforate.

The jacket space 58 of die casting 56 is supplied with cooling water by a system which is in series with a portion of the main cooling system already described.

From the channel 35 about the lower crank shaft bearing in castings 2i and 23, a hole 69 (Fig. 3) is drilled in such a way as to open at the surface of the wall 41 to communicate with a hole 18 (Fig. 6) in the plate 55 which leads to the portion 1| of the lower end of the jacket space 58 in the cover casting 56. Thus, the water in jacket space 58 cools the hot gases in chamber 51. As the water level rises to the top. of jacket space 58, it is permitted to pass from said space through the hole 12 in plate 55 (Fig. 6) and to enter the registering hole 13 in the cylinder casting 2| (Fig. 3), passing thence downwardly through the hole 15 (Figs. 2 and 3) to an inclined hole 16 (Fig. 3) which returns the water back to the main jacket space 29. In order to drill the inclined hole 16, it is necessary to enter the casting through the exposed face shown in Fig. 3, but this is covered by the imperforate area 11 of plate 55 (Fig. 6) so that the hole 16 afiords communication only between the vertical hole 1-5 and the main jacket 29 to which the water is returned.

The mixture supplied by carburetor II and entering the cylinders through ports 04 and 05 in the manner described, reaches the cylinders below the pistons therein and is compressed in the respective crank cases for delivery through the transfer passages 80 at the sides of the cylinders, one of which is shown in Fig. 2. It will be noted that this transfer passage has an unobstructed side wall opening parallel to the axis of the cylinder so that in the die casting of the part 2| the core, which makes the transfer passage, can be withdrawn endwise from the casting. At its outer end, the transfer passage communicates with the transfer port 0| which is bored through the cylinder sleeve 20 and through the adjacent portions of casting 2|. This boring is done from the opposite side of the cylinder at an appropriate angle from the exhaust manifold passage 40 to provide the exhaust ports02 and II. In each cylinder, three such ports are provided, as shown therefore, has less area in proportion to the diameter of the hole than do the ports 82 which enter the cylinder on minor chords thereof. The fact that the several ports are bored somewhat obliquely with reference to the axis of the cylinder locates the exhaust ports slightly nearer the cylinder heads than are the transfer ports 8|, thus enabling the exhaust ports to open earlier and close later than the transfer ports in accordance with approved practice.

The construction shown in Figs. 9 to 15 on sheets 3 and 4 of the drawings will now be described. While the device illustrated is a single cylinder engine, the manner in which the passages open to facilitate coring may be adapted to engines of the type shown in Figs. 1 and 2. Simabout a cylinder sleeve 20 a single casting unitarily providing a cylinder portion '2I0 and a crank case portion 220. In this instance, the crank case portion-220 includes the whole of the upper crank shaft bearing 85. The lower crank shaft bearing 86 is provided by a separate part and a plate 81 affords access to rounds the cylinder but, instead of opening to the end of casting 2I0, opens toward both sides thereof as is clearly shown in Figs. 10, 12, 14 and 15. At each side of casting 2I0, finished planiform surfaces are provided :to receive cover plates for completing the enclosure of the water jacket space. The cover plate 00 (Figs. 10, 11 and 12) performs no function other than to close the jacket space. The closure 81, however, at the the choke valve I00 (Fig. 10)

The water admitted through the hole 92 into the jacket space 95 rises to a level substantially for crank shaft filling the jacket space before it overflows the partition I02 which constitutes a dam extending between the closure 00 and the main cylinder block casting 2|0 and preferably constituting a part of the cylinder block casting as shown in Fig. 14. Having over-flowed the top 01' partition I02, the water passes downwardly along the inner end of the cylinder to the bottom of the well I03 where a pair of holes I04 and I05 communicating at right angles lead the water into the bearing casting 06. v

This casting, which provides the lower bearing 240, is provided with water passages communicating at the corners of a sub-' stantially square figure surrounding the bearing to keep the bearing cool. These passages I00, I01, I00 and I09, which are either drilled or cored, communicate with the exterior of the casting, being cut ofi by plugging the passagesat I ",1 II, H2 and H3, respectively. The hole I05 is intersected by the end of passage I09 closely adjacent to the point of intersection between passages I08 and I09 at one corner of the square. The water passes in both directions around the square I00 and I09 to passages I07 and the inner end of the cylinder. the side of cavity I20 which is nearest the outer end of the cylinder, a series of ports I 2I (Figsi 9 to 11) open through the sleeve 200 to the 111 conveniently be made in a single drilling from the open cavity across the cylinder to intersect operation by I20 completely both sides there- I20 which serves as a transfer port and also into place against a suitable shoulder.

This engine illustrates one way in which the spark plug I24 may be located at the side rather than the end of the cylinder head.

Because this engine is illustrated in an outboard motor structure and it is vent the return the exhaust support II6 with an annular flange I25 (Figs. 9 and 11) which serves as a dam. As illustrated, this dam has sufllcient height so that, regardless of the position of the motor, and even if it should be completely inverted, any water normally present in the shaft housing and tending, by reason of the inversion of the motor, to followthe exhaust gas passages, would be prevented from entering the channel IIIi leading to the cylinder.

The construction shown in Fig. 16 is, in general, similar to that disclosed in Figs. 9 to 15, inclusive, except that the carburetor casing I26 is, in this structure, cast integrally with the cylinder block casting 2. This drawing further illus trates the possibility that the top bearing for the crank shaft 240 may be provided by a separable crank case member I21.

Figs. 1'7 and 18 do not go into detail with regard to water passages or passages for the admission or transfer of the combustible charge. The purpose in Figs. 17 and 18 is to disclose an arrangement in which a single casting, preferably made by die casting, includes the engine cylinder 2I2, its jacket 2I3, the top and side walls of the crank case 2, the fuel tank- 2I5 and flanges 2I6, whichprovide fairing along the sides of the cylinder. Upon the fuel tank 2I5 is mounted another die casting which unitarily comprises a' cover I30 for the fuel tank and the front shroud I3I for the fly wheel I32. Applied to the fairing 2I6 at the rear of the cylinderis a spark plug cover shell I33, the interior of which communicates with the shroud to receive the blast of air centrifugally established by the rotation of the fly wheel, such blast being discharged across the end of the cylinder through an opening at I34 in shell I33. The margin of this opening is rounded at I35 to serve as a carrying handle.

An intermediate shroud section I3III extends from the front shroud I3I to the cover shell I33 and may be cast integral with fairing flanges M6.

The crank shaft 24I upon which fly wheel I32 is mounted, has its lower bearing in a removable closure I36 fitted to the lower end of the crank case. The bearing sleeve will ordinarily be extended to comprise a housing for the extension of the crank shaft 2 in an outboard motor structure, but it may be otherwise designed for other uses. It will be apparent that the fuel itself surrounds the sides of the entire end of the.

cylinder and the construction provides an extremely inexpensive and simplified way of constructing a light motor with comparatively few parts requiring assembly. As viewed i'n Fig. 17, the core used in forming the crank case is withdrawn downwardly, the core used in forming the fuel tank is withdrawn upwardly and the core used in forming the cylinder and its jacket space may be withdrawn endwise of the cylinder. The core used to form the transfer passage I38 and that used to form the exhaust passage I39 are withdrawn upwardly and downwardly, respectively.

' In each of the severalconstructions illustrated, the main or principal casting comprises the engine cylinder block and at least a portion of the crank case and is die cast under pressure upon the sleeve-like insert which constitutes the cylinder lining. In the construction first described,

the crank case is supported upon a transverse plane including the axis of the crank shaft and the core means forming that portion of the crank case included in'the aforesaid casting, is withdrawn axially of the cylinder, along with the core-means which form 'the transfer port. The core means forming the support for the cylinder sleeve and the core means forming the jacket portion of the main casting are withdrawn in the opposite direction upon the same" axis. The other core means withdrawn laterally provide passages for gas and give access to the portions of the principal casting in which'the ports are to be drilled through the casting and the liner sleeve.

In the constructions shown on Sheets 2 to 5 of the drawings, the ports are also arranged for the withdrawal in directions lateral with respect to the cylinder axis of the core means which form the respective passages for gas and which give access to the points where the ports are drilled into the principal casting.

In each of the constructions shown in Figs. 1 to 4, the closures applied over the cavities formed in the aforesaid corresponding operations perform additional functions in the support ofancillary equipment, such as the carburetor, or in the ggovision of supplemental passages and chamrs. I s

In each of the structures shown on Sheet 1 and Sheet 5, the spark plug cover is made not only to protect the spark plug but to provide a lifting handle for convenient manipulation of the engine and the outboard motor of which it may be part.

With particular reference to the construction shown in Figs. 1 to 8, inclusive, cylinder distortion is substantially eliminated by locating the holding screws for the cylinder head on the water jacket rather than the cylinder proper. In the construction shown in Fig. 9, the cylinder is extended sufficiently beyond the piston travel to receive the screws at a point where there is no piston bearing. In this construction, also, therefore, the portion of the cylinder traversed by the piston is free of distortion.

I claim:

1. In an engine having a crank case, cylinder and jacket, the combination in a single casting of a crank case portion having a hollow interior with walls progressively and unobstructedly open ing outwardly, a cylinder portion having a hollow cylindrical interior with walls unobstructedly opening outwardly, and a jacket spaced from said cylinder portion to provide a hollow cavity for coolant with walls progressively and unobstructedly opening outwardly, whereby each of said cavities is adapted to be formed by a die in a die casting operation,

2. In an engine having a crank shaft, crank case, cylinder, and jacket, the crank case comprising two complementary parts to provide an internal cavity and joined substantially in the transverse plane of the 'crank case, the combination in a single casting of the crank case part adjacent the cylinder, a cylinder block in which the cylinder is provided with a jacket space, said jacket space opening to the end of the cylinder opposite from the crank case with unobstructed wall surfaces adapted to permit of the withdrawal of a die following the formation of said casting in a die casting operation, the crank case portion included in said casting having an extension along the side of said cylinder constituting a transfer passage with unobstructed wall surfaces opening into the cavity of said crank case portion, whereby to be adapted for formation with said crank case cavity by die means withdrawable in a direction generally axial with respect to said cylinder, together with closures for the several cavities in said casting comprising a complementary crank-case section'for closing the space between the cylinder and the jacket.

3. An engine comprising a block provided with a horizontal cylinder and a jacket "cavity about the cylinder, a cylinder head including a closure for said jacket cavity and cylinder, said head having a water passage opening downwardly across said head and communicating with said jacket cavity solely at the top thereof, and means for introducing water into said iacket cavity at the bottom thereof, whereby said cavity is required to fill before water will discharge through said head.

4. The combination with a cylinder block having a cylinder and a jacket space opening to the end of the cylinder block, of a head having a complementary jacket space opening toward the end of the cylinder, said head constituting a closure for the cylinder and a closure for the jacket space, and an intervening gasket plate apertured to provide for restricted communication between the otherwise fully communicating jacket space of the cylinder and the jacket space of the head.

5. The combination with a cylinder block having a cylinder and a jacket space opening to the end of the cylinder block, of a head having a com plementary jacket space opening toward the end of the cylinder, said head constituting a closure for the cylinder and a closure for the jacket space, and an intervening gasket plate apertured to provide for restricted communication between the otherwise fully communicating jacket space of the cylinder and the jacket space of the head, said head having no jacketing across the end of the cylinder except a single discharge passage leading from said jacket space and extending substantially diametrically across said head.

6. In a device of the character described, the combination with a cylinder block and head, of a spark plug in the head, a cover for the spark plug secured thereabout, and a handle mounted on the cover for manipulation of said cylinder block.

7. In a device of the character described, the

combination with an engine having a cylinder provided with a head, of a spark plug in the head and a spark plug cover comprising a shell closely fitted to said head about said spark plug and formed to provide a carrying handle to facilitate the manipulation of said engine.

8. In a device of the character described, the combination with a casting providing at least one cylinder and a crank case section in integral connection with the end of the cylinder, of a transfer passage having a wall integrally formed in the angle between the crank case portion and cylinder, said passage opening into the crank case portion and extending rectilinearly along the cylinder wall, means at the other side of the cylinder'wall from said transfer passage comprising extensions of said wall to constitute intake and exhaust cavities, said cylinder having holes drilled from the respective cavities into the cylinder, certain of said holes being extended across said cylinder into said transfer passage to afford communication between said passage and cylinder, and closure means for said cavities.

9. In an engine, the combination of 8. cylinder block and a cooling jacket space opening to the same end of the block as the cylinder, the other end of said block being expanded to provide integrally a half section of a crank case, one side of the block being integrally formed to provide a transfer passage opening uninterruptedly into said crank case section and extending along the side of the block, the other side of the block having laterally opening adjacent cavities of substantial depth comprising mixture admission and exhaust cavities respectively, said block having holes affording, communication between the transfer passage and the cylinder and between the mixture admission cavity and thecylinder and between the cylinder and the exhaust cavity, said holes between the transfer passage and the cylinder and between the exhaust cavity and the cylinder being axially aligned to permit their formation in a single drilling operation, and closures for the ends and side of said block comprising a crank case section at one end of the block, a cylinder head at the other end of the block including a closure for said jacket space, and a closure for the said cavities, said last mentioned is closure being provided both with carburetion means and with an expansion chamber, the latter chamber communicating with the exhaust cavity.

10. In ane'ngine having a vertical crank shaft and horizontally reciprocable pistons in operative connection with the crank shaft, the combination with two crank case parts joined in a transverse plane at the crank shaft to provide upper, lower and intermediate bearings therefor and separate crank cases between the bearings, cylinders in which said pistons are reciprocable, said cylinders being formed in a single cylinder block casting of which the crank case section contiguous thereto is a part, a jacket likewise comprising a part of said casting and spaced from said cylinders to provide a jacket space for coolant about the cylinders, said jacket space and cylinders opening to the end of the casting opposite the crank case, means likewise forming an integral part of said casting providing separate transfer passages opening with unobstructed wall surfaces from the respective crank casm of said crank case section and extending thence along the sides of the respective cylinders, said cylinders being provided with ports opening from said passages into the cylinders, means at the sides of said cylinders opposite said transfer passage means comprising spaced laterally projecting walls defining laterally opening charge inlet cavities individual to the rethe closure means for the charge admission cavity comprising a carbureting device.

11. In an engine having a vertical crank shaft and horizontally reciprocable pistons in operative connection with the crank shaft, the combination with two crank case parts joined in a transverse plane at the crank shaft to provide upper, lower and intermediate bearings therefor and separate crank cases between the bearings, cylinders in which said pistons are reciprocable, said cylinders being formed in a single cylinderblock casting of which the crank case section contiguous thereto is a part, a jacket likewise comprising a part of said casting and spaced from said cylinders to provide ajacket space for coolant about the cylinders, said jacket space and cylinders opening to the end of the casting opposite the crank case, means likewise forming an integral part of said casting pro viding separate transfer passages opening with unobstructed wall surfaces from the respective crank cases of said crank case section and ex tending thence along the sides of the respective cylinders, said cylinders being provided with ports opening from said passages into the cylinders, means at the sides of said cylinders opposite said transfer passage means comprising spaced laterally projecting walls defining laterally opening charge inlet cavities individual to the respective cylinders and a single exhaust cavity common to the respective cylinders, the cylinders having ports opening into the respective cavities, the exhaust ports and the oppositely disposed transfer passage ports being in axial alignment in oblique relation to the cylinder walls, a cylinder head comprising a closure for the respective cylinders and the jacket space about the cylinders, and a closure connected with the side of the casting over said mixture admission cavity and said exhaust cavity and provided in communication with the respective cavities with a carbureting device and an expansion chamber, said last mentioned closure being formed to provide an internal jacket space intervening between the expansion chamber and the carbureting device and communicating with the jacket space of said engine at a plurality of points to afford circulation of coolant.

12. In an engine, the combination with a cylinder having laterally extending walls defining intake and exhaust cavities, said cylinder having port means affording communication with the respective cavities, of a closure plate provided with spaced chambers communicating with the respective cavities and an intervening partition out of registry with the wall means of said cylinder intervening between said cavities, and a plate intervening between said wall means and said closure and provided with apertures affording communication between the respective cavities, said plate having a coverportion spanning the offset between the partition of said closure and the wall of said cylinderintervening between said cavities.

13. A multi-cylinder engine comprising the combination with a crank shaft, connecting rod and pistons, of a crank case comprising two sections joined at said crank shaft and provided with upper, lower and intermediate bearings defining separate crank cases, a cylinder block comprising in a single casting a plurality of separate cylinders and the adjacent crank case section, and transfer means from the respective crank cases to the respective cylinders and jacket means for said cylinders, said cylinder block also having at its side opposite said transfer means charge admission cavities communicating with the respective cylinders and an exhaust manifold cavity communicating with each of said cylinders and providing an exhaust passage common thereto, said casting having laterally projecting wall surfaces and intervening partition means integrally forming said several cavities and being provided with holes opening through one of said well surfaces from the jacket space of said cylinder within said jacket means at a plurality of points adjacent remote sides of the respective cylinders, and closure means for the several cavities comprising charge forming means communicating with the charge admission cavities of the respective cylinders, expansion chamber means com- 5 municating with said manifold cavity and having an intervening jacket space disposed between the charge forming means and the expansion chamber means and communicating through said holes at spaced points with the jacket space of said cylinder block casting.

14. In an engine, the combination with a cylinder block casting including a crank case part integrally providing for one crank shaft bearing 15 and provided with a closure providing for another crank shaft bearing, of jacket means integrally forming a part of said casting and spaced therefrom at opposite sides of the casting, said jacket means having finished lateral surfaces, and an 20 internal cavity opening smoothly and unobstructedly toward said surfaces for the lateral retraction of dies used in the die casting of said cylinder block, together with closures applied laterally to said casting in connection with said jacket 25 means to confine a coolant therein about the cylinder of said casting.

15. In an engine, the combination of a casting integrally providing a cylinder and a jacket space opening smoothly and unobstructedly about said cylinder toward opposite sides thereof to facilitate the retraction of dies used in making said casting, of opposing closures for said jacket space connected with opposite sides of the casting, and a rib integral with said casting and abutted by one of said closures and constituting a flow directing means for controlling the circulation of coolant within the jacket space.

16. In an engine having a die cast cylinder block, the combination with a cylinder casting 0 having cylinder admission and exhaust Passages on two sides communicating with the cylinder and having jacket spaces opening oppositely to the other two sides, said jacket spaces and passages having walls smoothly and uninterruptedly 5 opening outwardly from the cylinder to facilitate the withdrawal of dies, and closures applied to the four sides of the cylinder casting in registry with the respective passages and spaces.

17. In an engine, a die cast cylinder block comprising a cylinder, an integral jacket wall spaced from the cylinder at opposite sides thereof, the

' space between the jacket wall and cylinder opensite sides of the cylinder, the casting being approximately rectangular in cross section, and

closures applied to said jacket walls at the sides of said block and in spaced relation to said cylinder to confine a coolant about said cylinder,

19. An engine comprising a die-cast cylinder block, having formed integral therewith, a crank case section and a fuel tank section, said fuel tank section having a cavity partially surrounding the crank case section and a lower portion of the cylinder block.

20. In a horizontally disposed engine, the combination with a single die casting unitarily com- 22. In an engine, the combination with an upprising a cylinder block having a laterally openright crank shaft and a horizontally reciprocable ing cylinder cavity, a crank case section having piston in operative connection therewith, of a a vertically opening crank case cavity and a fuel cylinder in which said piston is reclprocable, a 5 tank section having an upwardly opening fuel crank case provided with bearings for the crank reservoir cavity, of closures applied to said casting shaft, a portion of said crank case being integral about the several cavities aforesaid. with said cylinder, and a fuel reservoir integral 21. In an engine subject to tilting and having with said crank case portion and extending paran underwater exhaust, the combination with a tially about the crank case, a closure for said 10 cylinder having an exhaust port and an expanreservoir, a flywheel on said crank shaft, and sion chamber with which the exhaust port coma shroud for said flywheel of which at least a municates, of a flange surrounding said exhaust portion is mounted on said closure. port and constituting a dam for trapping in the expansion chamber water running through the WARREN C. CONOVER. l5 expansion chamber toward said port. a 

